SWT Series Screw Air Compressors

In industries such as food and beverage, pharmaceuticals, electronics, textiles and precision coating, compressed air sometimes comes into direct contact with the product or packaging. In such cases "oil content" is no longer a minor indicator open to negotiation — a single drop of oil mist can mean an entire batch scrapped, a customer complaint, or even a failed inspection notice.

The Fusheng SWTⅡ/SWTⅢ dry oil-free screw air compressor is made for these "zero tolerance" situations. It keeps lubricating oil out from the compression chamber onward, with air delivery of 6.9–66.8m³/min, power of 55–400kW and working pressure of 0.75–1.0MPa — a flagship large model in Fusheng's oil-free line-up.

How Many Kinds of Oil-Free Are There, and Why Dry Is More Thorough

What the industry usually calls an "oil-free air compressor" actually falls into two categories:

• Oil-injected machine plus multi-stage treatment: precision filters, activated carbon adsorption and the like bring oil content down very low, but strictly speaking this is "oil removal", and the filter elements saturate and need frequent replacement, carrying a "what if it fails" risk;
• Dry oil-free machine: no lubricating oil touches the compression chamber at all; the rotors run without contact thanks to timing gears and precise clearances, so no oil contamination arises in principle.

SWT is the latter. Its compression chamber is completely oil-free, and the compressed air delivered is oil-free at the source, without relying on downstream treatment as a fallback, greatly reducing the filtration burden and risk downstream.

Unique Design and a Super Coating: Oil-Free with Real Air Output

A dry oil-free machine faces a natural challenge: to avoid contact, a clearance must be left between the rotors, and that clearance causes gas backflow and lower efficiency. Many oil-free machines are therefore "very clean but very power-hungry, with air output that will not rise".

SWT's answer is to apply a super coating to the rotors, combined with a unique design, raising compression efficiency while staying oil-free and ultimately balancing "completely oil-free + stable and reliable + greater air output". For the user this means: cleanliness without having to compromise much on energy efficiency.

Air-Cooled, Water-Cooled or VSD: How to Choose

The SWT series offers a fairly complete product matrix, covering at least three directions in the specification table:

Fixed-speed air-cooled series: cooled by air, with no need for a circulating-water system; simple to install and highly mobile, suited to sites where water is inconvenient or investing in a cooling-water system does not pay.

Fixed-speed water-cooled series: high cooling efficiency and little affected by ambient temperature, suited to high-power, long continuous running where the plant has circulating water. The water-cooled models in the table also list cooling-water demand, which needs to be counted together with the plant water system during selection.

VSD water-cooled series: adds VSD control on top of water cooling, with speed following air-demand swings to cut running cost further. VSD models are more efficient and energy-saving and lower running cost, and for lines whose air demand varies noticeably this step usually offers the clearest economics.

Specifications at a Glance

The model specification table also includes fields such as discharge pressure, main motor power, noise, cooling-water demand, air outlet size, dimensions and weight; for the figures of each model, refer to the full specification charts lower on the page.

Industries and Applications

• Food and beverage: compressed air often contacts materials and packaging directly, so oil-free is a basic threshold;
• Pharmaceuticals and medical devices: clean air is a necessary condition for compliant production;
• Electronics and semiconductors: even trace oil contamination can affect product yield;
• Textiles and chemical fibres: air-jet looms and texturing equipment have high demands on air-supply cleanliness;
• Precision coating and pneumatic control: oil contamination affects coating adhesion and valve service life.

Selection Advice

1. Confirm the cleanliness class first: requirements for oil content, dew point and dust content vary widely by process; use them to decide whether drying and filtration are still needed after an oil-free machine;
2. Size the model by maximum air demand, choose the control method by typical conditions: the peak sets the model size, the size of the swings decides whether VSD is needed;
3. Let cooling follow site conditions: with stable circulating water and higher power, give priority to water cooling; where water is limited or a mobile layout is needed, choose air cooling;
4. Count the whole-life cost: the value of an oil-free machine lies not only in clean air but also in fewer filter replacements and lower downtime risk.

Conclusion

For most industries, compressed air only needs to be "good enough"; but in cleanliness-sensitive industries, oil-free is the bottom line, not a bonus. The SWT dry oil-free screw air compressor makes that bottom line the foundation of the product, while the super coating design pulls efficiency back up as far as possible — which is probably why it has become Fusheng's flagship oil-free model.